public boolean isValid(String s) {

if (s.length() % 2 != 0)

return false;

String[] chars = s.split("");

Stack<String> stack = new Stack<>();

for (String c : chars) {

try {

switch (c) {

case ")":

if (!stack.pop().equals("("))

return false;

break;

case "}":

if (!stack.pop().equals("{"))

return false;

break;

case "]":

if (!stack.pop().equals("["))

return false;

break;

default :

stack.push(c);

}

} catch(EmptyStackException e) {

return false;

}

}

return stack.isEmpty();

}

}